Perhaps you should try some spelling variations:
petra » petro (Expand Search), petre (Expand Search), petera (Expand Search), petroa (Expand Search), pera (Expand Search)
petru » pentru (Expand Search), peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (Expand Search)
petriov » peteriov (Expand Search), petroiov (Expand Search), periov (Expand Search), petrov (Expand Search), petrisv (Expand Search)
petrio » peterio (Expand Search), petroio (Expand Search), perio (Expand Search), petris (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((((petra OR petru) OR petr) OR petriov) OR (petrio OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petra OR petru) OR petr) OR petriov) OR (petrio OR petri)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petra OR petru) OR petr) OR petriov) OR (petrio OR petri)) o.s.*.